M64：黑眼星系特写

M64：黑眼星系特写

ByNASA中文

2023年7月20日 M64: The Black Eye Galaxy Close Up Image Credit: NASA, ESA, Hubble, HLA; Processing: Jonathan Lodge Explanation: This magnificent spiral galaxy is Messier 64, often called the Black Eye Galaxy or the Sleeping Beauty Galaxy for its dark-lidded appearance in telescopic views. The spiral’s central region, about 7,400 light-years across, is pictured in this reprocessed image from the Hubble Space Telescope. M64 lies some 17 million light-years distant in the otherwise well-groomed northern constellation Coma Berenices. The enormous dust clouds partially obscuring M64’s central region are laced with young, blue star clusters and the reddish glow of hydrogen associated with star forming regions. But imposing clouds of dust are not this galaxy’s only peculiar feature. Observations show that M64 is actually composed of two…

螺旋星系NGC 1398的环与棒

螺旋星系NGC 1398的环与棒

ByNASA中文

2023年7月12日 Rings and Bar of Spiral Galaxy NGC 1398 Image Credit: Mark Hanson; Data: Mike Selby Explanation: Why do some spiral galaxies have a ring around the center? Spiral galaxy NGC 1398 not only has a ring of pearly stars, gas and dust around its center, but a bar of stars and gas across its center, and spiral arms that appear like ribbons farther out. The featured deep image from Observatorio El Sauce in Chile shows the grand spiral galaxy in impressive detail. NGC 1398 lies about 65 million light years distant, meaning the light we see today left this galaxy when dinosaurs were disappearing from the Earth. The photogenic galaxy is visible with a small telescope toward the constellation of the Furnace (Fornax). The…

M94: 双环星系

M94: 双环星系

ByNASA中文

2023年6月7日 M94: A Double Ring Galaxy Image Credit & Copyright: Brian Brennan Explanation: Most galaxies don’t have any rings of stars and gas — why does M94 have two? First, spiral galaxy M94 has an inner ring of newly formed stars surrounding its nucleus, giving it not only an unusual appearance but also a strong interior glow. A leading origin hypothesis holds that an elongated knot of stars known as a bar rotates in M94 and has generated a burst of star formation in this inner ring. Observations have also revealed another ring, an outer ring, one that is more faint, different in color, not closed, and relatively complex. What caused this outer ring is currently unknown. M94, pictured here, spans about 45,000 light years…

M101

M101

ByNASA中文

2023年6月2日 Messier 101 Image Credit: NASA, ESA, CFHT, NOAO; Acknowledgement – K.Kuntz (GSFC), F.Bresolin (U.Hawaii), J.Trauger (JPL), J.Mould (NOAO), Y.-H.Chu (U. Illinois) Explanation: Big, beautiful spiral galaxy M101 is one of the last entries in Charles Messier’s famous catalog, but definitely not one of the least. About 170,000 light-years across, this galaxy is enormous, almost twice the size of our own Milky Way. M101 was also one of the original spiral nebulae observed by Lord Rosse’s large 19th century telescope, the Leviathan of Parsontown. Assembled from 51 exposures recorded by the Hubble Space Telescope in the 20th and 21st centuries, with additional data from ground based telescopes, this mosaic spans about 40,000 light-years across the central region of M101 in one of the highest definition…

模拟: 盘状星系的形成

模拟: 盘状星系的形成

ByNASA中文

2023年5月31日 Simulation: A Disk Galaxy Forms Video Credit: TNG Collaboration, MPCDF, FAS Harvard U.; Music: World’s Sunrise (YouTube: Jimena Contreras) Explanation: How did we get here? We know that we live on a planet orbiting a star orbiting a galaxy, but how did all of this form? Since our universe moves too slowly to watch, faster-moving computer simulations are created to help find out. Specifically, this featured video from the IllustrisTNG collaboration tracks gas from the early universe (redshift 12) until today (redshift 0). As the simulation begins, ambient gas falls into and accumulates in a region of relatively high gravity. After a few billion years, a well-defined center materializes from a strange and fascinating cosmic dance. Gas blobs — some representing small satellite galaxies…

邻近螺旋星系M101刚发现的超新星

邻近螺旋星系M101刚发现的超新星

ByNASA中文

2023年5月22日 Supernova Discovered in Nearby Spiral Galaxy M101 Image Credit & Copyright: Craig Stocks Explanation: A nearby star has exploded and humanity’s telescopes are turning to monitor it. The supernova, dubbed SN 2023ixf, was discovered by Japanese astronomer Koichi Itagaki three days ago and subsequently located on automated images from the Zwicky Transient Facility two days earlier. SN 2023ixf occurred in the photogenic Pinwheel Galaxy M101, which, being only about 21 million light years away, makes it the closest supernova seen in the past five years, the second closest in the past 10 years, and the second supernova found in M101 in the past 15 years. Rapid follow up observations already indicate that SN 2023ixf is a Type II supernova, an explosion that occurs after…

西班牙舞者螺旋星系

西班牙舞者螺旋星系

ByNASA中文

2023年5月8日 The Spanish Dancer Spiral Galaxy Image Credit: ESA, NASA, Hubble; Processing: Detlev Odenthal Explanation: If not perfect, then this spiral galaxy is at least one of the most photogenic. An island universe containing billions of stars and situated about 40 million light-years away toward the constellation of the Dolphinfish (Dorado), NGC 1566 presents a gorgeous face-on view. Classified as a grand design spiral, NGC 1566 shows two prominent and graceful spiral arms that are traced by bright blue star clusters and dark cosmic dust lanes. Numerous Hubble Space Telescope images of NGC 1566 have been taken to study star formation, supernovas, and the spiral’s unusually active center. Some of these images, stored online in the Hubble Legacy Archive, were freely downloaded, combined, and digitally…

星系NGC 3628

星系NGC 3628

ByNASA中文

2023年4月14日 Portrait of NGC 3628 Image Credit: Image Credit & Copyright: Mike Selby & Mark Hanson Explanation: Sharp telescopic views of NGC 3628 show a puffy galactic disk divided by dark dust lanes. Of course, this portrait of the magnificent, edge-on spiral galaxy puts some astronomers in mind of its popular moniker, the Hamburger Galaxy. It also reveals a small galaxy nearby (below), likely a satellite of NGC 3628, and a very faint but extensive tidal tail. The drawn out tail stretches for about 300,000 light-years, even beyond the left edge of the frame. NGC 3628 shares its neighborhood in the local universe with two other large spirals M65 and M66 in a grouping otherwise known as the Leo Triplet. Gravitational interactions with its cosmic…

M100: 宏伟的螺旋星系

M100: 宏伟的螺旋星系

ByNASA中文

2023年4月8日 M100: A Grand Design Spiral Galaxy Image Credit: NASA, ESA, Hubble; Processing: Judy Schmidt Explanation: Majestic on a truly cosmic scale, M100 is appropriately known as a grand design spiral galaxy. It is a large galaxy of over 100 billion stars with well-defined spiral arms that is similar to our own Milky Way Galaxy. One of the brightest members of the Virgo Cluster of galaxies, M100 (alias NGC 4321) is 56 million light-years distant toward the constellation of Berenice’s Hair (Coma Berenices). This Hubble Space Telescope image of M100 was taken with the Wide Field Camera 3 and accentuates bright blue star clusters and intricate winding dust lanes which are hallmarks of this class of galaxies. Studies of variable stars in M100 have played…

鲁宾的星系

鲁宾的星系

ByNASA中文

2023年4月5日 Rubin’s Galaxy Image Credit: NASA, ESA, B. Holwerda (University of Louisville) Explanation: In this Hubble Space Telescope image the bright, spiky stars lie in the foreground toward the heroic northern constellation Perseus and well within our own Milky Way galaxy. In sharp focus beyond is UGC 2885, a giant spiral galaxy about 232 million light-years distant. Some 800,000 light-years across compared to the Milky Way’s diameter of 100,000 light-years or so, it has around 1 trillion stars. That’s about 10 times as many stars as the Milky Way. Part of an investigation to understand how galaxies can grow to such enormous sizes, UGC 2885 was also part of An Interesting Voyage and astronomer Vera Rubin’s pioneering study of the rotation of spiral galaxies. Her…